NCT05456165

Study of an Individualized Vaccine Targeting Neoantigens in Combination With Immune Checkpoint Blockade for Patients With Colon Cancer

A Randomized, Open-Label, Phase 2 Study of a Patient-Specific Vaccine Targeting Neoantigens in Combination With Immune Checkpoint Blockade for Patients With Colon Cancer With Minimal Residual Disease Following Surgical Resection and Standard Adjuvant Chemotherapy

• Status: Withdrawn
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 0 (actual)
• Sponsor: Gritstone bio, Inc. · Industry
• Sex: All
• Age: 12 Years
• Healthy volunteers: Not accepted

Summary

The primary objective is to assess and characterize the antitumor activity and safety and tolerability of adjuvant treatment with an individualized neoantigen vaccine called GRT-C901/GRT-R902 (chimpanzee adenovirus \[ChAd\] and self-amplifying messenger RNA \[samRNA\] vectors), in combination with checkpoint inhibitors. Antitumor activity will be based on molecular response in patients with colon cancer who have circulating tumor deoxyribonucleic acid (ctDNA) following surgical resection.

Detailed description

Tumors harboring non-synonymous deoxyribonucleic acid (DNA) mutations present peptides containing these mutations as non-self antigens in the context of human leukocyte antigens (HLAs) on the tumor cell surface. A fraction of mutated peptides results in neoantigens capable of generating T cell responses that exclusively target tumor cells. Sensitive detection of these mutations allows for the identification of neoantigens unique to each patient's tumor to be included in a personalized cancer vaccine that targets these neoantigens. This vaccine regimen uses two vaccine vectors as a heterologous prime/boost approach (GRT-C901, ChAd as prime and GRT-R902, samRNA as boost) to stimulate an immune response. This study (GRANITE-ADJUVANT) will explore the anti-tumor activity of this individualized, patient specific immunotherapy in combination with checkpoint inhibitors.

Conditions

• Colonic Neoplasms
• Colorectal Neoplasms

Interventions

Type	Name	Description
DRUG	GRT-C901	An individualized neoantigen cancer vaccine using an adenovirus vector administered via intramuscular (IM) injections at Visit 1 and boost at Visit 6.
DRUG	GRT-R902	An individualized neoantigen cancer vaccine using a self-amplifying mRNA (samRNA) vector administered via IM injection at Visits 2, 4, 9, and 12.
DRUG	Atezolizumab	Dose of 1680 mg administered once every 4 weeks (Q4W) via intravenous (IV) infusion at Visits 1-13.
DRUG	Ipilimumab	Dose of 30 mg administered via subcutaneous (SC) injection only with the first dose of GRT-C901 at Visit 1 and GRTR902 at Visit 2.
DRUG	Adjuvant chemotherapy	Administered according to standard of care.

Timeline

• Start date: 2022-05-19
• Primary completion: 2022-09-01
• Completion: 2022-09-01
• First posted: 2022-07-13
• Last updated: 2024-12-31

Locations

3 sites across 1 country: United States

Regulatory

• FDA-regulated drug study